Tank bleeder valve



Jan. 6, 1942. w. J. MacARTHUR 2,269,031

TANK BLEEDER VALVE Filed Jul 1, 1939 Emmi-mm FIG.3

WILLIAM J. MAOARTHUR TORNE) Patented Jan. 6, 1942 UNITED STATES TANK BLEEDER VALVE William J. MacArthur, Los Angeles, Calif.

Application July 1, 1939, Serial No. 282,443

2 Claims.

' The object of the invention is to provide an apparatus for automatically draining the layer of free water which accumulates in tanks holding crude petroleum, petroleum distillates, and the like.

The invention is best described with reference to the attached drawing, in which Fig. 1 is an elevation of an illustrative embodiment of the invention, parts being broken away to show details of internal construction;

Fig. 2 is a fragmentary section in plan, as on the line 2-2 of Fig. 1, and

Fig. 3 is a section, as on the line 3-3 of Fig. 2, of a modified form of the mating grids 21 and 3 I.

Referring to the drawing: I is a hollow body or case, as of cast iron, provided with a cover plate I l retained by a plurality of clamp bolts l2. The case has on its lower side a threaded collar l3 to receive an inlet pipe, and may also beprdvided with a removable clean-out plate l4 covering an opening not shown in the lower side of the case. The cover plate is provided with an outlet tube l5 which is shown as broken off and may be threaded or flanged for pipe connection.

Centrally the cover plate is provided with a stuifing box IS, a gland I1, and a follower l8 which is urged by a spring H to compress flexible packing 20.

The functioning portion of the device consists of two mating circular grids, one of which is movable 'in relation to the other. Describing first the movable grid element: a stem 2| passes thence through space above the grids into outlet connection I5. I

Two alternative types of concentric ribs are shown. In the form-shown at the right side of the Fig. l the ribs 21 and 3| are rectangular in section and the spaces between them are predetermined in the machining of the two elements and are of constant width regardless of the relative positions of the two grids, to the pointwhere the ribs of the lower element are wholly withdrawn from the spaces between the ribs of the upper element. In the form shown in Fig. 3 the circular ribs are oppositely beveled and the spaciing between the opposed ribs may be varied by raising and lowering the stem and with it the lower grid assembly.

The functioning of this device depends on the fact that the surface tensions of hydrocarbon oils materially exceed that of water, and a very narrow annular channel may be so adjusted in width as to permit waterto flow freely and to shut off the flow as soon as oil tries to enter the channel. In my experience the most suitable spacing between the two grids ranges from 93 inch for gasoline to about inch for heavy crude oils. The most accurate machining of the two grids to ensure concentricity and even spacing is essential.

With the apparatus coupled to the drain pipe of an oil tank in the upright position shown, water willflow through the channels between the grids until the water layer in the tank is comthrough the stuffing box and is connected at its upper end with a pivoted link 22 and hand lever 23 to be raised and lowered manually through a short distance. At its lower end the stem is provided with a flange 24, a plurality of deep radial ribs 25 forming a spider, a rim ring 26 slidingly fitting within the case, and a plurality of upwardly projecting, circular and concentric ribs 21 supported by said spider.

The stationary grid element has a central hub 28 bored to fit stem 2 I, a flange 29 resting on the upper edge of the case, a plurality of deep radial ribs 30, and a plurality of downwardly projecting, circular and concentric ribs 3|.

These grids, as shown, are so formed that the adjacent ribs 21 and 3| leave narrow annular cannels 32 for the passage of water. The direction of flow through the device is indicated by arrows in Fig. 1; through the inlet connection 33 into the space 34 below the pair of grids, then in parallel through all of the channels 32 between the ribs 21 and 3| constituting the grids, and

pletely Withdrawn and oil enters the case. As this oil lies below the grids and cannot pass through, no fluid will pass even when water has again collected in the tank, until the oil is flushed out. For this purpose the hand lever 23 is depressed until the spacing between the two grids is sufiiciently wide to allow the oilto pass through and be followed by water. In this position the valve acts as an automatic stop, but manual flushing is required to reestablish drainage. If placed in the inverted position, water collecting in the tank after draining will gradually displace the oil from the case and, in the absence of thick emulsion, will again start to flow through the valve after an interval of cessation. It is highly desirable to provide a strainer in the inlet pipe to the device to" stop sediment and prevent too rapid fouling of the apparatus.

While the above descriptionrefers only to a circular form, it will be evident that the ribs of the two grids could be straight and parallel and the case be rectangular without in any manner changing the results produced by the device.

2. An automatic tank bleeding valve comprising: a case with inlet and outlet openings; a fixed grid arranged across said case between said openings and a movable grid mating with said fixed grid to leave a plurality of narrow channels for the passage of liquid laterally through said grids, the walls defining each said channel being substantially parallel, and means for adjusting the spacing between said grids to controllably vary 10 the width of said channels.

WILLIAM J. MACARTHUR. 

